/Engine/Plugins/Runtime/GeometryProcessing/Source/GeometryAlgorithms/Public/Arrangement2d.h
Insert new point into segment EID at parameter value T If T is within Tol of endpoint of segment, we use that instead.
[FIndex2i](API\Runtime\GeometryCore\FIndex2i) split_segment_at_t ( int EID, double T, double Tol )